Plasma arc torches are used in the cutting and marking of metallic materials. A plasma arc torch generally includes a torch body, an electrode mounted within the body, a nozzle with a central exit orifice, electrical connections, passages for cooling and arc control fluids, a swirl ring to control the fluid flow patterns, and a power supply. Gases used in the torch can be non-reactive (e.g., argon or nitrogen), or reactive (e.g., oxygen or air). The torch produces a plasma arc, which is a constricted ionized jet of a plasma gas with high temperature and high momentum.
Though most plasma arc torches share the same basic operation, the consumables used to operate plasma arc torches vary widely. Some plasma arc torches employ translating electrodes in order to initiate the plasma arc, while others use start-cartridges for the same purpose. Still other plasma torches use high frequency start circuits to initiate the plasma arc. There are, of course, many other variations from plasma torch design to plasma torch design, including differently designed nozzles, swirl rings, shields. While the various designs each have advantages and disadvantages, it is often troublesome for a user who owns multiple types of plasma cutting machines to carry the variety of consumables needed to operate all the machines.
Furthermore, hand-held torches are now being used in ever more intricate situations, including those where access to portions of the workpiece can be difficult. Automated (mechanized) torches are being used to cut special shapes, including cuts having bevel surfaces. One way to make such cuts is to angle the torch head, such that the plasma arc emitted from the torch is not perpendicular with a planar workpiece that is being cut. Expensive and extensive automated systems have been manufactured with devices to automatically rotate torches to perform bevel cuts.
Most hand-held plasma cutting torches have a torch head that is fixed at an angle between about 90° and about 115° relative to the handle. While this configuration is well suited for many cutting applications it is not ideal for cutting into sharp corners or pockets and many gouging applications. While a straight torch with a trigger may be easy to manufacture, it would be limited to these relatively infrequent applications.